title: Small ligands that neither bind to nor alter the structure of d(GA x TC)n sequences in DNA.
abstract: Three minor-groove binding ligands have been used to study the characteristics of two d(GA x CT)n DNAs embedded in longer DNA fragments. The binding of mithramycin, netropsin or Thia-Net to these sequences has been studied using DNAse I footprinting. None of these ligands appeared to bind to d(GA x CT)5 nor to d(GA x CT)22 extensively, although with mithramycin some protected bonds were detected at the very edge of these sequences. In general, these small ligands did not enhance the DNAse I cleavage patterns at the alternating d(GA x CT)n flanking sequences located near DNA regions where the drug was bound. The d(GA x CT)n sequences could act as a rigid block in which it is not easy to propagate structural changes, whereas other sequences flanking the binding sites showed cleavage enhancements.
authors.affiliation: Departamento de Biología Molecular y Celular, Centro de Investigación y Desarrollo, CSIC, J. Girona-Salgado, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Vaquero
authors.forename: J
authors.initials: J
authors.lastname: Portugal
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D018983:DNA Footprinting; D003850:Deoxyribonuclease I / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008024:Ligands; D008969:Molecular Sequence Data; D009429:Netropsin / Q000378:metabolism; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D008926:Plicamycin / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism
chemical_list: D008024:Ligands; D009838:Oligodeoxyribonucleotides; D013844:Thiazoles; C071601:Thia-Net; D009429:Netropsin; D004247:DNA; D003850:Deoxyribonuclease I; D008926:Plicamycin